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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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Adding Classes

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About the <head>

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CSS

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CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

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JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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HTML 

              
                <svg viewBox="0 0 0 0" style="position: absolute; z-index: -1; opacity: 0;">
  <defs>
    <linearGradient id="boxGradient" gradientUnits="userSpaceOnUse" x1="0" y1="0" x2="25" y2="25">
      <stop offset="0%"   stop-color="#27FDC7"/>
      <stop offset="100%" stop-color="#0FC0F5"/>
    </linearGradient>

    <linearGradient id="lineGradient">
      <stop offset="0%"    stop-color="#0FC0F5"/>
      <stop offset="100%"  stop-color="#27FDC7"/>
    </linearGradient>

    <path id="todo__line" stroke="url(#lineGradient)" d="M21 12.3h168v0.1z"></path>
    <path id="todo__box" stroke="url(#boxGradient)" d="M21 12.7v5c0 1.3-1 2.3-2.3 2.3H8.3C7 20 6 19 6 17.7V7.3C6 6 7 5 8.3 5h10.4C20 5 21 6 21 7.3v5.4"></path>
    <path id="todo__check" stroke="url(#boxGradient)" d="M10 13l2 2 5-5"></path>
    <circle id="todo__circle" cx="13.5" cy="12.5" r="10"></circle>
  </defs>
</svg>


<div class="todo-list">
  <label class="todo">
    <input class="todo__state" type="checkbox" />
    
    <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 200 25" class="todo__icon">
      <use xlink:href="#todo__line" class="todo__line"></use>
      <use xlink:href="#todo__box" class="todo__box"></use>
      <use xlink:href="#todo__check" class="todo__check"></use>
      <use xlink:href="#todo__circle" class="todo__circle"></use>
    </svg>

    <div class="todo__text">Do a very important task</div>
    
  </label>

  <label class="todo">

    <input class="todo__state" type="checkbox" />

    <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 200 25" class="todo__icon">
      <use xlink:href="#todo__line" class="todo__line"></use>
      <use xlink:href="#todo__box" class="todo__box"></use>
      <use xlink:href="#todo__check" class="todo__check"></use>
      <use xlink:href="#todo__circle" class="todo__circle"></use>
    </svg>

    <div class="todo__text">Another important task</div>
    
  </label>

  <label class="todo">
    <input class="todo__state" type="checkbox" />
    
    <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 200 25" class="todo__icon">
      <use xlink:href="#todo__line" class="todo__line"></use>
      <use xlink:href="#todo__box" class="todo__box"></use>
      <use xlink:href="#todo__check" class="todo__check"></use>
      <use xlink:href="#todo__circle" class="todo__circle"></use>
    </svg>
    
    <div class="todo__text">Not so important task</div>
  </label>
</div>
!

CSS 

              
                @duration: 0.8s;

.todo-list {
  background: #FFF; 
  font-size: 20px;
  max-width: 15em;
  margin: auto;
  padding: 0.5em 1em;
  box-shadow: 0 5px 30px rgba(0, 0, 0, 0.2);
}

.todo {
  display: block;
  position: relative;
  padding: 1em 1em 1em 16%;
  margin: 0 auto;
  cursor: pointer; 
  border-bottom: solid 1px #ddd;
  
  &:last-child { border-bottom: none; }
}

.todo__state {
  position: absolute;
  top: 0;
  left: 0;
  opacity: 0;
}

.todo__text {
  color: saturate(#1B4A4E,15%);
  transition: all @duration/2 linear @duration/2;
}

.todo__icon {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 100%;
  height: auto;
  margin: auto;
  
  fill: none;
  stroke: #27FDC7;
  stroke-width: 2;
  stroke-linejoin: round;
  stroke-linecap: round;
}


.todo__line,
.todo__box,
.todo__check {
  transition: stroke-dashoffset @duration cubic-bezier(.9,.0,.5,1);
}


.todo__circle {
  stroke: #27FDC7;
  stroke-dasharray: 1 6;
  stroke-width: 0;
  
  transform-origin: 13.5px 12.5px;
  transform: scale(0.4) rotate(0deg);
  animation: none @duration linear; //cubic-bezier(.08,.56,.04,.98);
  
  @keyframes explode {
    //0% { stroke-width: 0; transform: scale(0.5) rotate(0deg); }
    30% { 
      stroke-width: 3;
      stroke-opacity: 1;
      transform: scale(0.8) rotate(40deg);
      //animation-timing-function: cubic-bezier(.89,.01,.95,.51);
    }
    100% { 
      stroke-width: 0;
      stroke-opacity: 0;
      transform: scale(1.1) rotate(60deg);
      //animation-timing-function: cubic-bezier(.08,.56,.04,.98);
    }
  }
}

.todo__box { 
  stroke-dasharray: 56.1053, 56.1053; stroke-dashoffset: 0;
  transition-delay: @duration * 0.2; 
}
.todo__check {
  stroke: #27FDC7;
  stroke-dasharray: 9.8995, 9.8995; stroke-dashoffset: 9.8995;
  transition-duration: @duration * 0.4; 
}
.todo__line {
  stroke-dasharray: 168, 1684; 
  stroke-dashoffset: 168;
}
.todo__circle { 
  animation-delay: @duration * 0.7; 
  animation-duration: @duration * 0.7; 
}

.todo__state:checked {
  
  ~ .todo__text { transition-delay: 0s; color: #5EBEC1; opacity: 0.6; }
  
  ~ .todo__icon .todo__box { stroke-dashoffset: 56.1053; transition-delay: 0s; }
  ~ .todo__icon .todo__line { stroke-dashoffset: -8; }
  ~ .todo__icon .todo__check { stroke-dashoffset: 0; transition-delay: @duration * 0.6; }
  ~ .todo__icon .todo__circle { animation-name: explode; }
  
}

html { background: #ddd; }
html { height: 100%; display: flex; }
body { width: 100%; margin: auto; }
!

JS 

              
                console.clear();

setTimeout(function(){
  document.querySelector('input[type="checkbox"]').setAttribute('checked',true);
},100);
/*

// Javascript was initially used, but wasn't really necessary. Javascript droppped, but left here for archival purposes.

var todoTemplate = function(id){ 
  return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 25" class="todo__icon">
    <defs>
      <mask id="myMask${id}" maskUnits="userSpaceOnUse" x="0" y="0">
        <g stroke="#FFF" fill="none">
          <path class="todo__line" d="M21 12.3h168"/>
          <path class="todo__box" d="M21 12.7v5c0 1.3-1 2.3-2.3 2.3H8.3C7 20 6 19 6 17.7V7.3C6 6 7 5 8.3 5h10.4C20 5 21 6 21 7.3v5.4"/>
          <path class="todo__check" d="M10 13l2 2 5-5"/>
        </g>
      </mask>
    </defs>
    <rect fill="url(#todoGradient)" mask="url(#myMask${id})" width="100%" height="100%" />
    <circle class="todo__circle" cx="13.5" cy="12.5" r="10" />
  </svg>`
};

var todos = [ ...document.querySelectorAll('.todo') ].forEach(activateTodo);

function offsetPath(path, offset){
  var length = path.getTotalLength();
  path.style.transition = 'none';
  path.style.strokeDasharray = length + ' ' + length + offset;
  path.style.strokeDashoffset = length; 
  setTimeout(function(){ path.style.transition = null; },20);
  return length;
}

function togglePath(path, toggle, offset = 0){
  var length = offsetPath(path, offset);

  function updatePath(toggle){
    return path.style.strokeDashoffset = ( toggle ? -offset : length );
  }

  updatePath(toggle);
  return updatePath;
}

function activateTodo(todo, i){
  
  todo.insertAdjacentHTML('afterbegin', todoTemplate(i));
  
  var line = todo.querySelector('.todo__line'),
      updateLine = togglePath(line, false, 4);

  var box = todo.querySelector('.todo__box'),
      updateBox = togglePath(box, true);

  var check = todo.querySelector('.todo__check'),
      updateCheck = togglePath(check);

  var toggle = false;

  todo.addEventListener('click', function(){
    toggle = !toggle;
    updateLine(toggle);
    updateBox(!toggle);
    updateCheck(toggle);
    if ( todo.classList ) { todo.classList[ toggle ? 'add' : 'remove' ]('todo--checked'); }
  });
  
}

*/
!
999px

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